Improvement in rock-drilling engines



G. H. REYNOLDS. ROCK-DRILLING ENGINE.

Patented Nov.2, 1875.

Bren tor.-

UN E STATE PA EN OFFICE.

cnoneen. nnliinonns, on NEW. YORK, N. Y, lisslcnonrro HIMSELFL',

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- IMPRQVE E T in""RoCKDRuuNeQE em Es.

V Specification iorming part of Letters Patent N o. 169,58 '7ydatodNovember 2, 1875;

j a September 2 1875.

To'a-ll whom it may concern Be it known that I, GEORGE H, REYNOLDS, ofNew York city, in the State of New York, have invented certain new and'uset'ul Improvements in Rock-Drill Engines, of which-the following is aspecification r I have devoted much timefand labor to the production ofan engine which shall work successt'ully without valves,reciprocating'with a high degree velocity and to about theright extentunder. all conditions. My present invention is designed more perfectlyto accomplish the same object; i

With this mode of operation, without valves, it is important that thetime of the covering and uncovering of the ports by the movement of thepiston should be very nicely adjusted; and it is-important that when aport begins to be uncovered it shall immediately expose a large area tothe passage of the steam through the port. .i

I have arranged my ports to terminate in a ring or annular channel,extending all around the interior of the cylinder. piston has moved sofar as to commence to uncover a port it opens the entire area quitearound the piston to the movement of the steam. When the piston isclosing a port there remains a liberal opening. for the movement of thesteam until the edge of the piston has arrived at the closing position,and then it at once closes the space quite around the piston.

I have provided for the movement of the steam across the extended areathus provided by gathering it in a comparatively narrow channel in oneportion, casting the cylinder with a corresponding high ridge on itsexterior along the proper'line, and coring a crooked passage, by whichthe ring of steam-space before referred to is jumped or traveled overwithout forming a communication therewith.

The accompanying drawings form a part of this specification, andrepresent what I consider the best means of carrying out the inventionin its application to an ordinary rockdrill.

Figure l is a section, which, in order to cut through both the receivingand discharging ports, is madeon the line 00 y z in Fig. 2-that is tosay, the upper half of Fig. 1 is a section The moment the 3 applicationfiled '1 I on the linear y, and the lower half of Fig. is

a section on the line 3 z. Fig. 2. is section on the line 8 s in Fig. 1.

Similar letters of reference indicate like parts in both the figures.

A is the body of the cylinder, pr vidcd with heads, stuffing-boxes, andmeans for turning the drill as the piston reciprocates'. B is adoublepiston, forged or otherwiseiformed on a single stout stem, whichconnectsthe pistons and the drill. .The pistons'are placed at the properdistance apart, and 'thezports are so arranged that when the piston hasbeen thrown to one. end of the cylinder-the steam is received at thatend through a liberal passage, and it is exhausted from the oppositeend. As soon as the piston has been thrown its movement changes thesteam-connections,

a crossand it is impelled violently back again. With steam of areasonably high pressure the rockdrill,-properly attached, willreciprocate from ten to twelve complete doublestrokes per second.

The ports and the broad passages or chambers connected therewith outsideof the cylinder, being ot' master importance in this construction, willbe designated by several separate letters. The port through which steamis admitted is marked M. The broad chamber into whichit is received ismarked M. This chamber M extends quite around the cylinder. The portthrough which. steam is exhausted or discharged into the atmosphere ismarked P. A long narrow passage, extending parallel to the cylinder, andat a distance therefrom greater than the thickness of the chamber M onthat side, is marked P Each end of the passage P bends inward toward thecylinder, and communicates with the interior of the cylinder through themedium of a port or hollow channel, P extending quite around thecylinder. Two channels, through which, when the piston is at or neareither end of its stroke, the steam is allowed to flow from the centralspace between the two pistons to the nearest end of the cylinder, aremarked B. Each end of these channels is bent inward, and communicateswith the interior of the cylinder through the medium of the ports orhollow channels R extending quite around the cylinder. .Thejsteam,-i-ntraversing through tlre'lpas'sagefR, is compelled-atone "p'ointgzto passov'er the' port-P At this poin't'the' metal of the cylinder isthickened, and the passage is bent outward, so as to leave a sufficientthickness of metal between it and the port P as: indicated; by=-"R When,in the'w'orkingt'ofi 'my"engine?atithe high velocity required foreconomy in this line of engineering, the piston moves toward either endof its stroke and commences to"uncover one of the ports R it allows afree flow of the steam through the uncovered area, not of an ordin aryiport, but: of anzannular p2 ssageaquite around the piston. Steamtherefrom flows through the passage R thence through the passage R, andenters freely into the cylinder ain'- advance-' of the. front end :ofthe -piston.=

lhe pressure generated there stops the :mo-

inentum of theipiston before it-has reached the:

However-weak theJ-steam i may be, and however violent'the motion, the

end .of its stroke.

rchance rof. arresting the motion of the piston "by destroying-ritszmomentum is-.in'creased by :the :suddenw closing'lof i the:entire port?and the v uim prisoningrofi the. steam in advance of '2 the #:piston,jso thatzit cannotflowbackward. The r iarea -iistthengreatest possibleuntil the piston r has icutnitfloff, .a-nd then r. as suddenly as.possi- .bles thersteam is'iim'pri'soned, rand comp'elled zto 1:serveiasia wcus'hionwin advance of theip'iston, firstdiminishingixtherstroke, and :then vh aste-n- :iin'gethereturn-stroke'bf the. piston. rreturm'stroke,-.the1 'moment thepiston-has Ibezgunikto":uncover thevzport' it uncovers a i-large.

ssarea, andf theststeam entersfreely.

'Dhe sameBoHstruetion oirall the :ports makes 1 eiwch'angeso'fi"condition1 at each wreciprov cationimor'ewigorous. When the:pis-tonl'opens r or closes the port P it does itrvery. rapidly, withthe. largest I possible mriea; and the same is 't'rue'o'f each port; Inconsequence of "this peculiarity each port may be narrower than'wouldotherwise be allowable.

,The bending of the port or passage R R to "crossthe other "port',' Pnot -onl'y avoids any interferen'ceofa'currents and communication ofsteam from one passage to the other, but also maintains a uniformity inthe thickness of the cylinder, avoids'contortions in cooling, andreduces the liability to fracture.

It is more important in my cylinder than in -;thoseusually employed:thatithe -boreshall be cno. H- REYNOLDS.

Witnesses:

PHILLIPS ABBOTT, GHASwOMST-ETSON.

